there's this app called Grammarly that you can check if you have "plagiarized" or you can just type any sentence of the paper and if you click on any of the links and if you see that it looks exactly like your paper then you have plagiarized your paper
Explanation: Out of the four options given being, word processor, Internet, Encyclopedia, and Dustball Software. Answer is (Dustball Software: it's a plagiarism checker.) Hope this helps!